1. Field
The disclosed embodiments relate to a device for separating and detecting the faulty position of fasteners, more particularly blind rivets, in a continuously operating conveyor apparatus by means of which the fasteners are supplied to an automated joining machine wherein each fastener in the normal case is followed by a spacer.
Furthermore the disclosed embodiments relate to a method for separating and detecting the faulty position by means of the device.
2. Brief Description of Related Developments
Automated riveting machines for joining large-format sheet metal parts in the aircraft industry are supplied with a continuous stream of blind rivets through supply tubes. In order to prevent the blind rivets from jamming in the supply tube or conveyor tube each blind rivet is followed by a spacer. An external diameter of the blind rivets and spacers is each time slightly smaller than an internal diameter of the supply tube. There are frequently faults as the supply tube is loaded with blind rivets and spacers. In these cases the blind rivets are introduced for example turned round by 180° into the supply tube or a spacer is missing so that two blind rivets follow directly after one another. Such faulty positions of the blind rivets and missing spacers can lead to breakdowns in the operating cycle of the following automated riveting machine. Distinguishing between the spacers and blind rivets in the conveyor tube is carried out with a test fork. The opening width of the test fork corresponds roughly to the cross-sectional geometry of the break-off pin of the inserted blind rivets. If the blind rivet lies with the correct orientation in the supply tube—that is the rivet body lies in the conveyor direction—then the fork can slide substantially free of resistance over the break-off pin, and the blind rivet is supplied via a switching gate to the rivet inserter of the automatic riveting machine. If on the other hand a spacer is located in the supply tube then the test fork does not reach its end position within the predetermined time and the spacer is ejected.
As a result of the high supply speed of the rivets and the mechanical stress through the spacers there is a high degree of wear and risk of breakdown with the test fork. Furthermore an incorrect position of the blind rivets in the supply tube cannot be reliably differentiated from a general breakdown, such as for example a missing spacer or jamming of the test fork.